1. Field of the Invention
The present invention relates to an apparatus for performing communication with another vehicle having similar positional data based on broadcast positional data. The present invention also relates to an avoidance operation when it is recognized that there is a possibility of a collision with another vehicle.
2. Description of the Related Art
Systems for collecting a variety of information using a vehicle mounted communication apparatus, systems for collecting destination information of each vehicle to be utilized in traffic control, and a variety of other systems have all been proposed.
Inter-vehicle communication has been proposed where a moving or stopping vehicle will notify another vehicle of its actions or of information obtained in communication between the vehicles.
With such inter-vehicle communication, along with useful data, unnecessary information is often transmitted and received. For example, even if information of future traveling/stopping of a vehicle which has brushed is received, it usually has no meaning. Therefore, in inter-vehicle communication, there are many requests to effectively select useful data from all received data.
Furthermore, Japanese patent laid-open publication No. Hei 7-333317 discloses an apparatus that transmits/receives position information between movable bodies and raises an alarm when both movable bodies are approaching a predetermined distance.
Moreover, there has been proposed a system for averting vehicle collision by performing communication between vehicles (inter-vehicle communication) and measuring the distance between the vehicles. The “SS boomerang system” is one such system. In the “SS boomerang system,” an electromagnetic wave is broadcast, and a response is returned by vehicles which receive that signal. The response time is measured to calculate the distance between the vehicles to allow the possibility of collision to be reduced.
However, with inter-vehicle communication for measuring the distance between vehicles based on the response time of the transmitted electric wave, accurate motion information of another vehicle other than the distance between the vehicles is difficult to obtain.
In addition, it is not negligible that the avoidance operation carried out by the both vehicles that have possibility of a crash is not necessarily appropriate.